Re: [Discuss-gnuradio] uhd_fft missing
On Mon, Mar 17, 2014 at 3:19 PM, Rick Farina sidh...@gmail.com wrote: Just to confirm, is everything working properly for you now, Chris? Yes, with the portage mods below: package.keywords: ~net-wireless/gnuradio-3.7.3 ~amd64 ~dev-python/pyqwt-5.2.0 ~amd64 ~dev-libs/boost-1.53.0 ~amd64 ~dev-util/boost-build-1.53.0 ~amd64 ~net-wireless/uhd-3.7.0 ~amd64 package.use: net-wireless/gnuradio grc uhd examples Also, it took me a while to figure out that the UHD examples were zipped up and placed at /usr/share/doc/gnuradio-3.7.3/examples/ Thank you, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] uhd_fft missing
Hello, Using gentoo linux I installed uhd and gnuradio with the commands emerge uhd and emerge gnuradio. According to http://gnuradio.org/redmine/projects/gnuradio/wiki/HowToUse: GNU Radio comes with a large variety of tools and programs... The most commonly used tools include uhd_fft Unfortunately I do not have uhd_fft on my system. I do have uhd_cal_rx_iq_balance, uhd_cal_tx_iq_balance , uhd_images_downloader, uhd_cal_tx_dc_offset, uhd_find_devices, and uhd_usrp_probe. According to http://gnuradio.org/redmine/projects/gnuradio/wiki/InstallingGRFromSource: If you want to be able to use USRP devices, you need to install UHD before installing GNU Radio. Questions: Q1: Why do I not have uhd_fft on my system? Q2: What is the technically going on that leads to the warning about installing UHD before gnuradio? What are the consequences of installing UHD after GNU Radio? Q3: Which package provides the file uhd_fft: GNU Radio, UHD, or something else? Thank you, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] uhd_fft missing
On Sun, Mar 16, 2014 at 12:48 PM, Sylvain Munaut 246...@gmail.com wrote: Since you're using gentoo, I think the most likely scenario is that the 'wx' USE flag is disabled. Sylvain, Thank you for your help. Turns out I the wxwidgets USE flag us set... but the uhd USE flag was unset. Rebuilding now, but I'm sure this will fix the problem. BTW, as you might guess, the uhd USE flag causes net-wireless/gnuradio to bring in net-wireless/uhd. I should have known something was up when I had to manually emerge uhd. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] uhd_fft missing
On Sun, Mar 16, 2014 at 12:31 PM, Marcus D. Leech mle...@ripnet.com wrote: If you're building from source, the source-build needs to know where UHD is installed on your system before it can build gr-uhd, since gr-uhd links again UHD libraries. Marcus, Thank you. In gentoo speak, what you said typically translates to The gnuradio ebuild has a uhd USE flag. Make sure the uhd USE flag is enabled. Well, I checked and sure enough it was disabled. I'm rebuilding now but I'm sure it will work correctly. Thanks again, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] trouble building uhd-3.6.2 for the zedboard
Hello, I am attempting to use GNU radio with a ZedBoard by following the tutorial here: http://gnuradio.org/redmine/projects/gnuradio/wiki/Zynq While using bitbake to create an OS to run on the board, I get an error while compiling uhd-3.6.2: /home/sdr/oe-repo/oe/build/tmp-eglibc/sysroots/x86_64-linux/usr/bin/armv7a-vfp-neon-oe-linux-gnueabi/arm-oe-linux-gnueabi-g++ -march=armv7-a -mthumb-interwork -mfloat-abi=softfp -mfpu=neon --sysroot=/home/sdr/oe-repo/oe/build/tmp-eglibc/sysroots/zedboard-zynq7 -O2 -pipe -g -feliminate-unused-debug-types -fpermissive -fvisibility-inlines-hidden -fpermissive -O2 -pipe -g -feliminate-unused-debug-types -O2 -pipe -g -feliminate-unused-debug-types -fpermissive -fvisibility-inlines-hidden -DNDEBUG -march=armv7-a -mthumb-interwork -mfloat-abi=softfp -mfpu=neon --sysroot=/home/sdr/oe-repo/oe/build/tmp-eglibc/sysroots/zedboard-zynq7 -O2 -pipe -g -feliminate-unused-debug-types -fpermissive -fvisibility-inlines-hidden -Wl,-O1 -Wl,--hash-style=gnu -Wl,--as-needed -Wl,-O1 -Wl,--hash-style=gnu -Wl,--as-needed CMakeFiles/benchmark_rate.dir/benchmark_rate.cpp.o -o benchmark_rate -rdynamic ../lib/libuhd.so.003.006 -lboost_date_time-mt -lboost_filesystem-mt -lboost_program_options-mt -lboost_regex-mt -lboost_system-mt -lboost_thread-mt -lboost_unit_test_framework -lrt -lusb-1.0 -lpthread -ldl -Wl,-rpath,/home/sdr/oe-repo/oe/build/tmp-eglibc/work/armv7a-vfp-neon-oe-linux-gnueabi/uhd/3.6.2-r0/build/lib: ../lib/libuhd.so.003.006: undefined reference to `.LASF9319' ../lib/libuhd.so.003.006: undefined reference to `.LASF9769' ../lib/libuhd.so.003.006: undefined reference to `.LASF9090' ../lib/libuhd.so.003.006: undefined reference to `.LASF13765' [these errors repeat hundreds of times] Does anyone know what this means, why I am getting this, or how to fix it? Thank you! Chris Steps to reproduce: install xubuntu 12.04, 64-bit in a VirtualBox VM sudo apt-get update sudo apt-get dist-upgrade sudo reboot sudo apt-get install dkms curl git build-essential gawk diffstat chrpath texinfo gparted sudo /media/VBOXADDITIONS_4.2.22_91556/VBoxLinuxAdditions.run sudo reboot sudo ln -s /usr/bin/make /usr/bin/gmake curl http://commondatastorage.googleapis.com/git-repo-downloads/repo repo chmod a+x repo mkdir oe-repo cd oe-repo ../repo init -u git://github.com/jpendlum/zynq-gnuradio-manifest.git ../repo sync cd ~/oe-repo/oe export PARALLEL_MAKE=-j 1 export BB_NUMBER_THREADS=1 TEMPLATECONF=`pwd`/meta-zynq-gnuradio/conf source ./oe-core/oe-init-build-env ./build ./bitbake bitbake gnuradio-dev-image ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Newbie need help with installing gnuradio 3.1.3
Pete, How did you solve this problem: While running ./bootstrap, I am getting the following error: [r...@fodora gnuradio-3.1.3]# ./bootstrap gr-trellis/doc/Makefile.am:51: `%'-style pattern rules are a GNU make extension Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Overrun when there shouldn't be
Juha Vierinen wrote: usrp_standard_rx* rx = usrp_standard_rx::make(UsrpNumber, DecimRate,2,-1,0,4096,4096); Using gnuradio 3.1.3 and applying the above change plus the gr_enable_realtime_scheduling(); change fixed my problem. I should try just making one of the two changes too to see which one does the trick. Thanks for your help! Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Overrun when there shouldn't be
Chris Stankevitz wrote: 3. Built and installed 3.1.3 (tar.gz) Just upgraded to the trunk and unfortunately have the same problem. (usrp_standard_rx* changed to a boost sptr, but otherwise code is the same.) Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Overrun when there shouldn't be
Chris Stankevitz wrote: Question: Why would 2 channels at 4MHz overrun while 1 channel at 8MHz not overrun? Fantastic news (for me): this problem does not occur in gnuradio 3.0.2 I thought to try an older version of gnuradio after I made the realization (with the help of a coworker) that my overrun problems are worse today than they were a year ago. FYI, my application is a dual channel GPS receiver which demands no overruns. I'd love to help find the source of the problem in newer versions of gnuradio... if anyone has any tests you'd like run, let me know. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Overrun when there shouldn't be
Hi,
I wrote a c++ program that grabs data from the USRP in an infinite loop
and does nothing with it. It overruns. Can anyone help me figure out why?
This runs on a 2.4GHz computer that isn't doing anything else. I'm
sampling the A and B channel of a BasicRX at 4MHz with shorts. CPU runs
about 15%. I've tried many different values for NumBytes. Profile
results show nothing abnormal. This is driving me nuts!
Thank you,
Chris
#include usrp_standard.h
#include iostream
using namespace std;
static const unsigned DecimRate = 16;
//-
//-
int main(int argc, char** argv)
{
static const int UsrpNumber = 0;
const unsigned Format = usrp_standard_rx::make_format(
16, // width across usb
0,// shift
true, // want Q
false // bypass halfband
);
usrp_standard_rx* rx = usrp_standard_rx::make(UsrpNumber, DecimRate);
static const int Mux = 0x33221100;
rx-set_decim_rate(DecimRate);
static const double DdcFreq = -12000e3;
static const int NumChannels = 2;
rx-set_nchannels(NumChannels);
for(int i = 0; i NumChannels; ++i)
{
rx-set_rx_freq(i, DdcFreq);
}
rx-set_mux(Mux);
rx-set_pga(0, 0);
rx-set_pga(1, 0);
rx-set_format(Format);
static const unsigned NumBytes = 4096;
char* Buffer = new char[NumBytes];
rx-start();
bool Overrun = false;
// Throw away first 32kB of data because it's fouled up
// with some kind of sinc
int NumTossed = 0;
while(NumTossed 32768)
{
NumTossed += rx-read(Buffer, NumBytes, Overrun);
}
while(true)
{
rx-read(Buffer, NumBytes, Overrun);
if(Overrun)
{
Overrun = false;
cerr Overrun\n;
}
//std::cout.write(Buffer, NumBytes);
}
rx-stop();
delete [] Buffer;
return 0;
}
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Re: [Discuss-gnuradio] Overrun when there shouldn't be
Eric Blossom wrote: Which OS are you running on? Are you running on a VM? Did you build and install the GR code, or did you just extract the usrp code and try to build it? In either base, which version are you using? Which FUSB method are you using? Have you build GNU Radio and attempted to run usrp_rx_cfile.py? Does it overrun? Thank you for your response. 1. Ubuntu 8.10 32bit and Ubuntu 8.04 64 bit 2. No VM 3. Built and installed 3.1.3 (tar.gz) 4. usrp_rx_cfile does not overrun (!) 5. I do not know what FUSB method means, but I like the sounds of it. Looking it up now. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] How to use usrp_oscope and usrp_fft
Mir Ali wrote: Can someone tell me how to use usrp_oscope.py and usrp_fft.py? I tried looking for answers on the archive but couldn't find any. Mir Ali: Launch the apps just like you would any other program. Just type usrp_fft.py then press enter. Select the frequency you want to look at using the text box in the corner. You can use abbreviations such as 4M instead of typing out 400. The blue squiggle line is a plot of power vs frequency. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Re: fusb::_reap: Interrupted System Call
On Thu, Oct 11, 2007 at 03:54:56PM -0400, Jared Jensen wrote: Does anyone know why I get fusb::_reap: Interrupted System Call frequently? There are no overruns, and my data seems good, but I keep getting this error. If it's meaningless, is there a way to suppress I get this when I run a USRP c++ app with a profiler. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Re: fusb::_reap: Interrupted System Call
Eric Blossom wrote: Try using oprofile instead. That's what I use. I don't have a problem with the messages, just trying to help the OP. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Overrun when there shouldn't be
Johnathan Corgan wrote: On Mon, Feb 9, 2009 at 7:07 PM, Chris Stankevitz cstankev...@toyon.com wrote: I wrote a c++ program that grabs data from the USRP in an infinite loop and does nothing with it. It overruns. Can anyone help me figure out why? Can you try it without the call to set_format()? Johnathan, Even without the call to set_format, I still get overruns. I also made some other changes: 1) Original code (overruns) 2) 1) minus set_format (overruns) 3) 2) with NumChannels==1 (no overruns) 4) 3) with DecimRate==32 vs 16 (no overruns) Test 3 not overrunning was no surprise since it's cuts the data in half. However, Test 4 note overrunning was a huge surprise because Test 4 pumps the same amount of data as Test 2 which does overrun. Question: Why would 2 channels at 4MHz overrun while 1 channel at 8MHz not overrun? Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] USRP1 ADCs in sync?
Are the USRP1 ADCs in sync? i.e. do they each sample on the same clock cycle? Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] USRP on 56ft mast: need long USB cable?
Hi, I'm putting my USRP and antenna on a 56 foot mast. For my application the USRP must be near the antenna. I'd rather not deal with the logistics of placing the computer on the mast as well. Any ideas on how I can get the USB data from the top of the mast to the ground where my computer is? ideas: - long USB2 cable - USB2 - ethernet (does this exist?) - Put computer atop the mast Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] USRP on 56ft mast: need long USB cable?
Chris Stankevitz wrote: - USB2 - ethernet (does this exist?) Does the USRP2 use ethernet to transmit data? I just saw a picture of it. CHris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] USRP2 backward compatibility questions
1. Does the USRP2 support the BasicRX daughterboard? 2. Does the USRP2 support the DBSRX daughterboard? 3. Does gnuradio-3.1.3 work with USRP2? 4. Does the USRP2 work with the usrp_standard_rx interface (in libusrp.so provided by gnuradio-3.1.3) 5. My application requires the USRP to use the external clock provided by my front end. It runs at 64 MHz. Will the USRP2 accept this 64 MHz clock? (I'm guessing not since it appears the USRP2 runs at a different frequency). I can provide a sine or square wave clock. I have an application that uses the BasicRX or the DBSRx. The only component of gnuradio I use is the usrp_standard_rx interface provided by gnuradio-3.1.3. I am researching the amount of work I will need to do to use the USRP2. I am interested in USRP2 because it transmits data over ethernet which has longer range than USB2. Thanks! Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] USRP2 backward compatibility questions
Chris Stankevitz wrote: 5. My application requires the USRP to use the external clock provided by my front end. It runs at 64 MHz. Will the USRP2 accept this 64 MHz clock? (I'm guessing not since it appears the USRP2 runs at a different frequency). I can provide a sine or square wave clock. Yes. From the FAQ (http://www.gnuradio.org/trac/wiki/USRP2GenFAQ): Does the external frequency reference have to be 10 MHz? Can I use 100 MHz? Actually, you can use 100 MHz as well, you will just need to change one line of the firmware to set the R-divider on the PLL. You can use any frequency for which the following equation has a solution: 100 MHz / N = Ref / R for which N and R are integers and smaller than 32,768 ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Decimation and filter in the USRP
Hi, Can someone describe the filter process that happens after decimation inside the USRP? I would like to reproduce it exactly when generating data I correlate with the USRP's output. Thank you, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Re: Decimation and filter in the USRP
Chris Stankevitz wrote: Can someone describe the filter process that happens after decimation inside the USRP? I would like to reproduce it exactly when generating data I correlate with the USRP's output. I found some answers in the pdf The USRP under a 1.5X magnifying lens Plus I just saw a question about specific tap values on the list... so I think I'm covered for now. Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] c++ question
Brett L. Trotter wrote:
I forgot that C++ doesn't support jagged arrays like C# so I created
this great little jagged array with the 2nd dimension 0 terminated (mask
of 0 isn't really useful anyway, so I used it like null) so that I could
figure out how many were in each degree. I've been googling and IRCing
and trying to figure out if there's a way to initialize a vector of
vectors as a constant in a class header file or something that would
hold these constants and coming up short on answers. Do I need to dump
all my data to a file and read it in? That seems poor for minimizing the
initialization delay. Is anyone willing to point me in the right direction?
1. You can initialize multidimensional c arrays at compile time:
int a[2][2] = {{1, 2}, {3,4}};
2. If I cared abound speed (like you do), I wouldn't use vector of
vector, rather a single long c-style array. (I'd use code to make it
appear as it if is a 2-d array eventhough it's 1-d.) And I'd use
Stream.read and Stream.write to read/write it to disk which will be very
fast. Using the example above:
int n = Rows * Cols;
int* a = new int[n];
// fill the array here using code
std::ofstream s(array.bin, std::ios::binary);
s.write(reinterpret_castconst char*(a), n * sizeof(int));
// subsequent loads will use the binary file:
std::ifstream s(array.bin, std::ios::binary);
s.read(reinterpret_castchar*(a), n * sizeof(int));
Chris
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Re: [Discuss-gnuradio] Predictable latency?
Geib, Jeffrey (Civilian) wrote: I have an application where I don't necessarily care what the latency is, but I need it to be predictable and/or constant. Is there a way to achieve this with the USRP hardware? USRP supplies data via USB. I believe the delay of USB data through the operating system and into your application is not predictable or constant. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] get a waveform of usrp clock 10~64MHz usingfile_sink
James Park wrote: Hi, is it possible to save a waveform of usrp clock using file_sink? I want to save the usrp clock signal like other transmit and receive signals, but due to lack of knowledge, have no idea. Thank you. I doubt you can do this. It would look like a 64MHz square wave. You could feed in a reference wave (perhaps from a signal generator or other accurate clock) and look at it's deviations from the reference freq to deduce what the 64MHz clock is doing. Maybe if you had 2 USRPs you could feed the clock of one into the RX of the second. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] 64MHz USRP Oscillator
Wireless Monster wrote: Hi All, I am having lots of issues with the USRP 64MHz (20ppm) on board oscillator which does not allow me to get exact and constant RF frequencies out of the RFX900 board. I can not really fix that in SW so I was thinking about replacing the 64MHz crystal with a more precise one. Has anybody a suggestion of which part to use? I have replaced the crystal with the 20ppm crystal, but I was unable to get an exact and constant frequency. I ultimately added a software PLL to track the clock errors. Before I upgraded my software PLL, I used a signal generator as an external clock source which worked very well. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] 8 bit samples have an odd spectrum
Johnathan Corgan wrote: You *may* be seeing an artifact of the truncation of the ADC samples. Johnathan: Thank you, that's exactly what it looks like. Adding USRP pga gain didn't help though. I'll get back to the group... Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] 8 bit samples have an odd spectrum
Matt Ettus wrote: Remember that while the ADCs are 12 bits, we carry 16+ bits of precision throughout the signal processing. Matt, How do you get 16 bits of precision from a 12 bit ADC? What does 16+ mean? I'm looking at the shorts coming from the USRP and I'm seeing values in the range [-3296 3264] which implies more than 12 bits... curious. FYI, we supposedly tuned our front end to saturate the ADC 1% of the time. Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] 8 bit samples have an odd spectrum
Matt Ettus wrote: Look at the samples in the scope sink. Do you see a pattern of A A B B C C D D, meaning instead of unique samples, is every one repeated? If so, it means that the halfband decimator is probably not being bypassed properly. Here are the first 100 8 bit samples from the USRP and the first 100 16 bit samples divided by 256. You'll notice that the 16 bit samples divided by 256 are larger than the 8 bit samples. Both are collecting ambient noise from my GPS antenna: Here are the first 100 8 bit samples from the USRP: -2 0 0 0 2 -1 0 0 0 -2 0 0 0 1 0 0 -1 -3 0 0 2 2 0 0 0 0 0 0 -3 0 0 0 2 2 0 0 2 0 0 0 0 1 0 0 -3 0 0 0 -6 0 0 0 -4 2 0 0 1 1 0 0 0 0 0 0 -2 0 0 0 3 0 0 0 -1 -2 0 0 1 -3 0 0 0 -1 0 0 0 -1 0 0 1 3 0 0 1 5 0 0 0 0 0 0 Here are the first 100 16 bit samples divided by 256: -1 3 2 2 -3 -2 -3 1 -2 1 -1 -1 1 -2 2 3 -2 1 1 -4 0 -2 -2 -3 0 -4 0 -2 0 2 5 2 2 0 5 1 1 1 3 1 -2 -3 -3 -5 1 3 0 0 4 -1 3 3 1 -4 1 -2 -1 -2 1 -6 -3 -2 1 3 -4 -1 -5 -2 -2 3 0 -2 -1 -3 2 4 2 2 4 -2 1 4 -1 1 1 3 0 0 -2 -2 -3 -1 0 0 -3 2 -3 -3 -2 0 ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] No decimation -- collect at 64MHz
Thanks for your reply. Johnathan Corgan wrote: You would have to modify the FPGA code to do so, but it is indeed possible if not trivial. Trivial is good! However, for it would probably take two weeks to get to the point where I can make the trivial change! The gr-radar-mono code does this (there are of course a lot of unrelated customizations to the FPGA code as well). I'm going to look at this. I'll be back with questions... Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] 8 bit samples have an odd spectrum
Hello, a) Here is a screenshot of 16 bit noise @ 12 MHz: http://img224.imageshack.us/img224/8981/16bitsb0.png b) Here is a screenshot of the same noise with 8 bit samples: http://img60.imageshack.us/img60/5852/8bitqg7.png c) 8 bit noise, tuned to 12.5 MHz http://img224.imageshack.us/img224/1596/8bitoffsetua5.png My questions: 1. Why does b) show a lobe while a) does not? 2. Why do b) and c) show lobes at the same pixels (vs shifted .5 MHz)? The spectrum should be entirely noise. The signal is from an antenna plugged into a front end that brings 1.57542GHz (GPS L1) to 12MHz. Thank you, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] No decimation -- collect at 64MHz
Hi, I am troubleshooting a problem with my GPS receiver. Is it possible to collect some 64 MHz data? I understand the collect will not be long because USB2 can't handle the bandwidth, but perhaps buffers on the USRP will allow me to make a 1ms collect? Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] gr.file_sink format...
Jonathan Friedman wrote: I'm using a usrp to digitize and write the samples to a file which I then import and process in Matlab. I do the same thing. What does your matlab code look like? i = fopen(filename); x = fread(i, 400, 'float32'); ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] USRP installation problem
Nan Zhang wrote: I tried to install the newly purchased USRP. However, plug in USB cable to my computer does not generate message of Found New Hardware as Do other USB devices work in the same port you're plugging the USRP in? Does the green LED on the USRP illuminate? Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] USRP enclosure
Where can I buy a USRP enclosure? I don't see it listed at http://www.ettus.com/custom.html Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Losing data during long collects
Bob McGwier wrote: There is insufficient dynamic range in any GPS signal on any ordinary mortals GPS antenna to use more than 8 bits. Not so if the signal is being jammed... ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Losing data during long collects
Robert Fitzsimons wrote: Just some comments on the code: int NumBytes = rx-read( (char*)Buffer, n*sizeof(short), Overrun); Your code doesn't do anyting if the read returns less then n*sizeof(short) bytes. Is that possible within the gnuradio code? pStream-write((char*)Buffer, n*sizeof(short)); Same here the write might not write all n*sizeof(short) bytes. Robert, You're exactly right, I assume that all the bytes are read and written! Thank you so much I'll fix it right away. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Reclocking URSP and phase imbalance
Gregory W Heckler wrote: I reclocked my USRP from 64 to 65.536 MHz Greg, Just out of curiosity, why did you do this? Related to GPS? Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Losing data during long collects
Dan Halperin wrote: USRP's cfile utility cannot write my data without overruns, so I use my own app which I have attached to this email in case anyone is interested. I will try Juha's recorder to see if it performs better. FWIW (maybe you've fixed the problem already), I would think that if this is the case then you're using the cfile script wrong. Are you using the '-s' switch (to halve the required disk bandwidth)? Hi Dan, Yes, I record the data as 16 bit shorts vs. 32 bit floats. At 4Msps complex data, this provides 16 megabytes per second which is within the capabilities of my 4 disk RAID0 array. Here are the results of the bonnie++ benchmark which reports my drive can write at 58 megabytes per second: Version 1.03 --Sequential Output-- -Per Chr- --Block-- MachineSize K/sec %CP K/sec %CP cstankevitz-lapt 4G 34335 44 58313 5 Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Losing data during long collects
Jeff Brower wrote: I've seen cases before where the drive does handle the throughput as advertised, but on an average basis. Under sustained, continuous write circumstances, when the drive reaches a new sector, multiple of sectors, or some other internal space boundary, extra time is taken for allocation... Jeff, Thanks again. Is it ever possible for all of these things to happen: 1. write data to disk using cfile 2. hard drive cannot keep up for whatever reason (new sector, etc) and data is lost 3. A USRP overrun condition does not occur Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Losing data during long collects
Hi, I'm using the USRP/DBSRX to record data for GPS. GPS tracking demands a continuous stream of data -- dropped bits make tracking impossible. 4Msps of complex data supplies 16 MB/s -- within USB2 bandwidth and my 4 disk RAID0 bandwidth. I record the data using my own c++ version of cfile. I never get an error or overrun condition from usrp_standard::read so it appears that everything is working fine. However, when I process the data it is clear that data is dropped -- approximately a few thousand samples every minute or two. I typically record data for one hour at a time. I read data from the USRP in batches of 8192 16 bit short samples. Anyone have any tips on tracking down why I am dropping data? Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Losing data during long collects
Eric Blossom wrote: If you're running Linux and writing to an ext3 filesystem, try remounting it as an ext2 filesystem. I've seen problems in the past when the ext3 filesytem posts its journal, however they showed up as overruns -- the filesystem wasn't keeping up. Eric, I used to have this problem when I was using ext3 on a slow hard drive. The problem manifested itself as a buffer overrun. Today I use ext2, have a 4 disk RAID0 that can handle 40MB/s sustained, and I get no overruns. Bug in your code? Are you double buffering or something? Are you properly handling locking between the producer and consumer? My code is pretty simple, so naturally (of course) I don't think it is buggy. I am double buffering. I will start recording with cfile and see if the problem goes away. I could also try a lower sampling rate. Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Losing data during long collects
Jeff Brower wrote: Is there a way for you to temporarily take file-write out of the equation? I.e. can your code look at the bitstream and know if it remains continuous / intact? The every minute or two thing makes me suspicious that some HDD related thing is going on. 16 MBbyte/sec is around 1 GByte/minute. Jeff, Thanks for your recommendation. I can indeed pipe the output of my data gathering app to the input of my GPS processor and see if the problem goes away. However, I suspect the problem is not HDD related for these reasons: 1. I'm using a 4 disk RAID0 (external eSATA) drive that supposedly can handle the throughput 2. When I was disk bound in the past, I would receive USRP overrun errors. I do not receive these errors when I am presently losing a few thousand samples out of every 480e6 CHris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Losing data during long collects
Chris Stankevitz wrote: Thanks for your recommendation. I can indeed pipe the output of my data gathering app to the input of my GPS processor and see if the problem goes away. BTW one problem with this approach is that I can only confirm that there is lost data by post processing. The symptoms are obvious: I lose tracking lock on a GPS satellite, but the root cause (jittery clock or cycle-slip or missing data) can only be determined via autopsy. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] DBSRX used for GPS: cycle slip
Heckler, Gregory W. (GSFC-596.0) wrote: Have you ruled out the USRP overflowing? I have had that problem bite me too. It causes all of the tracking channels to dump in my receiver, but I could see how it could also cause a jump in the frequency estimate (delay in time domain == shift in frequency domain) coming out of your FFT acquisition. Hi Greg, I ruled out a USRP overflow for two reasons: 1. When I recorded the data, there was no indication of overflow 2. When I perform a continuous acquisition, the frequency jumps, but the C/A offset does not. When data is lost, the C/A offset will jump also. However, I do have a dataset with missing data that gave no indication data was lost during the collect. I'm chatting about this in another thread Losing data during long collects CHris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] DBSRX used for GPS: cycle slip
Peter Monta wrote: How sudden are the shifts and how often do they happen? Do they look They are sudden (happen within 10 ms) and they happen about once a second. I visualize them by continuously acquiring a GPS signal and watching the peak move along the freq axis in the 3D plot of frequency vs. chip offset vs. power These are the DBSRX (MAX211x) parameters as they are in Greg Heckler's c++ driver: d_fdac = 127 d_gc2 = 31 d_diag = 5 d_div2 = 1 d_n = 6304 d_m = 2 d_dl = 0 d_ade = 0 d_adl = 0 d_osc = 3 d_cp = 1 d_r_int = 3 Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] DBSRX used for GPS: cycle slip
Gregory W Heckler wrote: Chris: So you are not tracking the signal in the traditional sense, only looking at the frequency and delay estimate of your FFT acquisition. How far spaced are your Doppler bins in the FFT acquisition? If you are using a 1 ms integration time, and hence a 500 Hz bin spacing, if the signal's true Doppler is towards the middle of a bin it is ambiguous which bin the peak power will reside in due to noise. I have observed that the USRP's clock is jittery (PLL tracking is only possible by opening up the bandwidth beyond the recommend 18 Hz for a 3rd order PLL), however I have never observed a 500 Hz instantaneous jump in frequency (which would cause all of the channels to dump). Do you have tracking data with multiple SVs which also point to a 500 Hz frequency jump? Greg, 1. Our acq doppler bins are spaced 100Hz apart. The sudden jump is 1000Hz (10 bins). As I said earlier, this problem only occurs on one of my DBSRX boards. On the faulty DBSRX board, the problem exists for all satellites. If it turns out the DBSRX board is not faulty, it could indicate that the parameters I'm passing to the DBSRX/MAX211x are on the hairy edge of being stable for the chip. 2. I have also noticed USRP's jittery clock. However, my 2nd order PLL is able to track it. One thing that concerns me about your setup is that you are sampling at 2Msps complex -- the bare minimum according to Nyquist. FYI I am using 4Msps. 3. I do not know what you mean by this: So you are not tracking the signal in the traditional sense, only looking at the frequency and delay estimate of your FFT acquisition. -- perhaps you can rephrase? Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] DBSRX used for GPS: cycle slip
Heckler, Gregory W. (GSFC-596.0) wrote: I was referring to the Doppler estimate output by your PLL over time (traditional tracking), whereas you indicated that you were looking at repeated acquisition attempts. Greg, While performing traditional tracking with a PLL using prompt accumulations, I noticed my PLL could not keep track. As a debugging tool I conducted repeated acquisitions and it was there I noticed that the freq was suddently changing -- aha the source of my PLL problem! This image should give you an idea of what we are doing. It's a matlab plot of various outputs from our traditional tracker. http://img233.imageshack.us/img233/4064/gpswm9.gif Thanks, I will take a look at the frequency being passed to DBSRX. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] DBSRX used for GPS: cycle slip
Hi, I am seeing sudden freq shifts at the local oscillator on the order of ~500Hz which make it impossible to track GPS. We suspect under certain conditions there are cycle slips in the DBSRX PLL. Questions: 1. Can someone provide a schematic of the DBSRX in pdf or tell me how to read the one at http://www.gnuradio.org/trac/browser/usrp-hw/trunk/dbsrx 2. What are the R and C values of the analog PLL filter on the DBSRX? Thank you, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] DBSRX used for GPS: cycle slip
Chris Stankevitz wrote: 1. Can someone provide a schematic of the DBSRX in pdf or tell me how to read the one at http://www.gnuradio.org/trac/browser/usrp-hw/trunk/dbsrx I found that I can open the .ps version. Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Help to record GPS samples.
ALeX wrote: Hello, I'm working on a Gps software in conjunction with a usrp and dbsrx. Unfortunately my dbsrx has an hardware problem and I can't acquire Gps samples. Can someone record samples in L1 frequency (1.57542 Ghz) for me in 6.4msps/complex or 6.4msps/shorts and make it available for download or upload on mine ftp server? I have a sample at 4Msps (not 6.4) complex shorts recorded witht the DBSRX that I can come to full GPS solution on. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] External clock with Rev 3: cut traces coming from crystal
Hi, I have a rev 3 USRP and I will be using an external clock. Instructions at http://gnuradio.utah.edu/trac/wiki/USRPClockingNotes report, among other things cut the traces coming from X2. Q1: Which of the X2 traces are coming from X2? Q2: If I should cut all the X2 traces, why not just desolder X2? Thank you, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Does DDC perform complex multiplication?
I found two diagrams which seem to indicate different kinds of multiplication: http://www.nd.edu/~jnl/sdr/docs/tutorials/6.jpg http://www.gnu.org/software/gnuradio/doc/ddc.png I hope the DDC performs complex multiplication because I am feeding it with one real signal (via BasicRX A:0) and would like to use both I and Q outputs in my application. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] c++ driver for BasicRX
Hi, Where can I find the c++ driver for the BasicRX daughterboard? Greg Heckler wrote one for the DBSRX which I have been using (thanks Greg): http://article.gmane.org/gmane.comp.gnu.radio.patch/28 Thank you, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] FFTW problem
Mohammad Hamed Firooz wrote: make[2]: *** [check-local] Error 1 make[2]: Leaving directory `/usr/sr make[1]: *** [check-am] Error 2 make[1]: Leaving directory `/usr/sr make: *** [check-recursive] Error 1 Can you post more of the error? It looks like you chopped off the last parts of the lines. It also looks like you chopped off some important lines before the ones you pasted. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Data Capture Problems
Ed Criscuolo wrote: 3) Any ideas on how to diagnose or fix it? If this were happening to me, I'd be curious about how many samples got written to disk. Was it an whole number of samples? Was it an even number like 10^6 or 2^10. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] the best file system for reading fast
Vincenzo Pellegrini wrote: Once I formatted it with the XFS filesytem, following Rayan's tip, it looked like I was getting the appropriate throughput... ext3 could not keep up with 4e6 short complex samples/sec. ext2 could, so I use ext2. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Re: laptop recommendations
John Stralka wrote: Everything worked (including the built-in wireless network adapter) Which reminds me: if you get a Dell laptop, do not get the Dell/Broadcom wireless card, get the Intel wireless card. Easier to setup in linux. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Threaded c++ only USRP cfile dump
Eric Blossom wrote: (Don't use the ext3 filesystem if you've got to stream continuously.) Ian, Eric: At Eric's suggestion, I switched to ext2 and as he guessed, I had no trouble writing 4e6 complex shorts/sec to disk with file_sink. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Threaded c++ only USRP cfile dump
Recently I have been asking questions about overruns, threaded blocks,
and c++ only USRP reading. My application requires uninterrupted data,
which I was unable to get from the USRP with my laptop, even just
recording data to a file_sink. Attached is a program that records data
from the USRP. It is entirely in c++ and uses threads to prevent losing
data by writing to the hard drive while it reads from the USRP.
Thanks to Ian Larsen for a C++-only USRP example and to Greg Heckler for
the DBSRX c++ driver.
In addition to the attached, you also need db_dbs_rx.cpp and db_dbs_rx.h
from http://lists.gnu.org/archive/html/patch-gnuradio/2007-08/msg0.html
Compile with -lusrp and -lpthread
Chris
#include db_dbs_rx.h
#include usrp_standard.h
#include fstream
#include iostream
//#include pthread.h
using namespace std;
#define NUMBUFFERS 16
#define NUMBYTES (4096*sizeof(short)*2/512*512)
void* Producer(void* Args);
void* Consumer(void* Args);
//-
//-
struct TSQueue
{
TSQueue();
~TSQueue();
char Buffers[NUMBUFFERS][NUMBYTES];
unsigned NumBytes[NUMBUFFERS];
unsigned Head, Tail;
bool Full;
bool Empty;
void Add(const char* in, unsigned n);
void Delete(char* out, unsigned n);
pthread_mutex_t* pMutex;
pthread_cond_t* pNotFullCond;
pthread_cond_t* pNotEmptyCond;
};
//-
//-
TSQueue::TSQueue()
{
memset(NumBytes, 0, sizeof(NumBytes));
Empty = true;
Full = false;
Head = 0;
Tail = 0;
pMutex = new pthread_mutex_t;
pthread_mutex_init (pMutex, NULL);
pNotFullCond = new pthread_cond_t;
pthread_cond_init (pNotFullCond, NULL);
pNotEmptyCond = new pthread_cond_t;
pthread_cond_init (pNotEmptyCond, NULL);
}
//-
//-
TSQueue::~TSQueue()
{
pthread_mutex_destroy (pMutex);
delete pMutex;
pthread_cond_destroy (pNotFullCond);
delete pNotFullCond;
pthread_cond_destroy (pNotEmptyCond);
delete pNotEmptyCond;
}
//-
//-
void TSQueue::Add (const char* in, unsigned n)
{
if(Full)
{
pthread_cond_wait(pNotFullCond, pMutex);
}
NumBytes[Tail] = n;
memcpy(Buffers[Tail], in, n);
++Tail;
if (Tail == NUMBUFFERS) Tail = 0;
if (Tail == Head) Full = true;
Empty = false;
pthread_cond_signal(pNotEmptyCond);
}
//-
//-
void TSQueue::Delete(char *out, unsigned n)
{
if(Empty)
{
pthread_cond_wait(pNotEmptyCond, pMutex);
}
n = NumBytes[Head];
memcpy(out, Buffers[Head], n);
++Head;
if (Head == NUMBUFFERS) Head = 0;
if (Head == Tail) Empty = true;
Full = false;
pthread_cond_signal(pNotFullCond);
}
//-
//-
struct TSProducerArg
{
TSQueue* pQueue;
usrp_standard_rx* pRx;
};
//-
//-
struct TSConsumerArg
{
TSQueue* pQueue;
ofstream* pStream;
};
//-
//-
void* Producer(void* q)
{
TSProducerArg* pArg = reinterpret_castTSProducerArg*(q);
TSQueue *pQueue = pArg-pQueue;
usrp_standard_rx* rx = pArg-pRx;
rx-start();
while(true)
{
bool Overrun;
char Buffer[NUMBYTES];
int Size = rx-read(Buffer, NUMBYTES, Overrun);
if(Size == -1)
{
cerr Problem endl;
}
else
{
if(Overrun)
{
cerr overrun endl;
}
pQueue-Add(Buffer, Size);
}
}
rx-stop();
return 0;
}
//-
//-
void* Consumer(void* q)
{
TSConsumerArg* pArg = reinterpret_castTSConsumerArg*(q);
TSQueue *pQueue = pArg-pQueue;
ofstream* pStream = pArg-pStream;
while(true)
{
unsigned n = 0;
char Buffer[NUMBYTES];
pQueue-Delete(Buffer, n);
pStream-write(Buffer, n);
}
return 0;
}
//-
//-
Re: [Discuss-gnuradio] Recovering x(t) from IQ samples
Jonathan Jacky wrote: Verilog is no more difficult or mysterious than C++, wxPython, autotools etc. Does it come with a debugger? I'd love to get into it, but things like learning how to debug/compile/etc are what scare me personally. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Receiving USRP bits in c++ (no blocks needed)
Ian Larsen wrote: If you're still interested, I'm about to upload a pure C++ Oscilloscope that I wrote to Sourceforge that does exactly what you're looking for, for the Basic TX and RX daughterboards only. Ian, I would love to have this!! Greg H. put a C++ DBSRX driver on the patches mailing list which I will incorporate into whatever you have. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Block example that processes on another thread
Can anyone direct me to a block that does its processing on a separate thread (i.e. other than the thread that calls gr_sync_block::work) Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Receiving USRP bits in c++ (no blocks needed)
Matt Ettus wrote: It's called usrp_rx_cfile.py Thanks, but I'm looking for a c++ app. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Losing data somewhere between USRP and hard drive
Hi, Thanks for your response. I would still like an answer to this question: Q1: If I use a usrp_rx_cfile.py to record data, and my app never reports Ou on the console, have all the bits been written to disk? usrp_rx_cfile.py is known to work ;) No doubt about it, but if the hard drive cannot keep up, I'm sure data will be lost. My goal is to setup a system that can record data to disk even with a slower hard drive, perhaps by creating a threaded file_sink with a large memory buffer. ubuntu 32 bit, with ext3. I will try ext2. Have you tried benchmarking your filesystem i/o throughput? How about testing for any pauses where nothing else can get done. E.g., posting the ext3 journal. I'm running on a laptop and I suspect I am going to have problem with hard drive speed and my solution will need to be in the application layer. But I will play with hdparm and family. 16MB/s * 8 bits/byte = 128Mbit/s Are you using gigabit ethernet? Yes. Network has plenty of room to spare according to task manager. Using crossover cable. The mystery here is why would gr give Ous when sending data over gigabit to a server that simply throws the data away. These Ous happen far less than the hard drive Ous. Thanks again for your help, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Receiving USRP bits in c++ (no blocks needed)
Does anyone have an example application that grabs data from the USRP (say Basic RX) and is entirely in c++? I don't need GR blocks, just the bits please. Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Losing data somewhere between USRP and hard drive
Hello, Q1: If I use a file_sink to record data, and my app never reports Ou on the console, have all the bits been written to disk? Q2: Does anyone have a suggestion about how I can avoid Ou messages when using file_sink? Q1 commentary: Sometimes the data I get from file_sink looks funky. It could be a problem with my implementation of my application, but I suspect the data is corrupted and I suspect it contains gaps eventhough no Ou was reported. Q2 commentary: Ramdisk doesn't work because I'm writing gigabytes of data. I am thinking maybe I could write a multithreaded file_sink that operates more cleverly than the currently implementation. I am sampling 4e6 complex short samples per second. I have also tried sending the data over TCPIP using file_descriptor_sink attached to a python socket with setblocking(0). Even when the receiving server is just throwing away the data (i.e. no disk access or processing) data is sometimes lost. Thanks for your help and suggestions, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] 64 bit vs 32 bit
Daniel O'Connor wrote: (ie I am wondering if anyone has done a comparison) My Gnuradio block which does processing in 64 bit doubles runs nearly twice as fast under 64 bit ubuntu over 32 bit ubuntu. Hardly a good comparison though since your blocks probably don't do the same thing. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] 64 bit vs 32 bit
Manaen Schlabach wrote: that I am using GNUradio yet. I heard that 32bit v. 64bit makes a difference with the newest python interpreters. Is this the case? Is Hi, I am running 32 and 64 bit versions of ubuntu on my Dell M90. On the 64 bit version, the USRP is not seen with an error similar to Unable to find USRP#0. I did not investigate further. I am confident I properly setup gnuradio/USRP/udevrules/permissions because I just went through the process on the 32 bit version. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] USRP's supplying values larger than 128
Dumb question: Why is the USRP supplying values outside -127/127 when it has on board an 8 bit ADC? Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] USRP's supplying values larger than 128
The USRP uses an AD9862 which has a 12-bit resolution ADC. D'oh, thank you Johnathan. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Eric's on vacation
Eric Blossom wrote: I wanted to let you all know that I'm taking some time off, and will be absent from the list (and the rest of the email world) for a while. Where are you going (in case we need to get ahold of you)? Chris ;) ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] how do I disable this buffer warning?
Trond Danielsen wrote: I also get a lot of messages like this, and I suspect it is the curse for doing vector processing on vectors of length other than powers of two. Am I correct? You get these messages when your blocks cannot keep up with the rate of data coming from the source. Some blocks (FFTs come to mind) operate more efficiently when given data in chunks of powers of two, but I would guess changing your vector length wouldn't help too much. You can write the data out to a file and read it back in. This way you will not lose any data (but you will run slower than real time). Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GPS on DBSRX
Ben Loftin wrote: Chris, I have successfully done coarse acquisition using the correlator developed here, Ben, Thanks for the reply. I now have a GPS acquisition routine and tracker running. I am using the DBSRX with about 60dB of gain on a puck style antenna. My trackers are producing the nav bits, but I still need to decode them (I plan to use GPStk for this). It is all implemented as a single gnuradio block. I will release the source when I get smart on the subject and get a final thumbs up from my company (which paid for it). Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Dayton
Matt Ettus wrote: Unfortunately, I had to cancel my trip to Dayton at the last minute. Ettus Research will not be represented there this year, but we hope to be back next year. What's going on in Dayton? ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] USRP Rev3 Schematic and external clock
Hi, I have a rev3 USRP board. I would like to drive it with an external clock which also drives my (external) RF front end. Where can I find schematics of this board or instructions/tips on using an external clock? Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] how to modify an existing source code without recompiling the entire gnuradio-core
When I modify a file in gnuradio-core, I type make sudo make install in the gnuradio-core directory. It seems to go quickly. What command do you issue after making a change to a .cpp in gnuradio-core? Chris pradeepbhat wrote: Hello guys, I am trying to modify the cpp files in gnuradio-core folder but after any modification I have to recompile every thing in the gnuradio-core, do you know a faster or a better way to do this thing. also, I can't run the code in the debugging mode. Thanks, Pradeep ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Frequency error in USRP.
Tarun Tiwari wrote: the local oscillators may not be perfect They definitely will note be perfect. But, the question is how do I recover the signal if my receiver clock does not synchronize to the desired frequency? In my application (GPS), I don't even know the desired frequency due to the doppler effect on the fast moving satellites. I use an acquisition routine to locate the frequency which uses FFTs in my custom block. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] GPS on DBSRX
Question: Has anyone successfully acquired a GPS signal using the DBSRX daughterboard? Is so, what kind of gain did you place before the board? Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Basic RX daughterboard: DC bias
Hi, When I run the basic RX daughterboard with no input cable attached, usrp_fft reports a signal at 0 Hz (which I assume to be some kind of DC bias created within the USRP or daughterboard). How can I remove this? Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] DBSRX and GPS - which gain?
What should I set the gain to (set_gain()) when receiving GPS signals on the DBSRX? I've been trying to use the guess and check approach with no luck. Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Troubleshooting GPS on DBSRX
Short Version: Please help me troubleshoot why I cannot acquire GPS with my USRP+DBSRX, but I can using KD7LMO's sample data recorded with USRP+DBSRX. Long Version: Hi, I wrote a GPS acquisition routine which operates inside a GR block fed by the USRP or gr.file_source. The acquisition routine is a variation of the weak signal approach presented in Fundamentals of Global Positioning System Receivers a Software Approach. My acquisition routine works great when applying GR's file_source on the KD7LMO USRP-recorded GPS samples. However, I cannot acquire using a USRP source_c. Please share any tips you have. Here are some things I tried: 1. Antenna/environment Assuming GPS was simply not visible from my window, used the Leadtek 9546EVK (http://tinyurl.com/yqx3nv) with the same GPS antenna I used on the USRP. The Leadtek was able to acquire and track GPS with C/N0 40. I have tried using this antenna on the USRP with and without a 30dB low noise amplifier. 2. Birdies When commanded to tune to GPS L1 (1.57542GHz), the DBSRX front end tunes to a slightly higher freq (r=8,n=3151,Fs=4e6) and compensates with a software DDC. Witht these values of r and n, a birdie can be seen at L1+1MHz in USRP's FFT and in an HP spectrum analyzer hooked to a GPS antenna near the USRP. I eliminated it with different values of r and n (r=2, n=788) and a slightly higher DDC. I accomplished this by adding a hack at line 289 of db_dbs_rx.py that works when Fs=4e6: # Avoid birdie when LO is set close to L1 if freq==157542: best_r = 2 best_n = 788 3. Signal generator Thinking I was improperly tuning the USRP, I connected a signal generator to it and verified that L1 was being brought to baseband. However I was frightened to see some artifacts on the USRP FFT that do not appear on the HP spectrum analyzer. They appear out of the noise for strong input signals (-75dBm). 4. Enclosure I do not have an enclosure for my USRP. This could be a problem. 5. Others KD7LMO managed to record a beautiful signal (40+ C/N0) and I don't think he did anything fancy except use an amplifier. I wonder if i am doing something boneheaded e.g. setting the gain to zero. Q: Should I be worried about the birdie I saw? Q: Does my hack do what I think it does? Q: Should I be worried about these artifacts I see? Q: What does set_gain() do on the USRP with a DBSRX board? What should I set it to? Thanks for your help and ideas. I am a c++ guy new to this antenna stuff. Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Carrier offset on DBSRX.
Trond Danielsen wrote: Okay, I think I understand. But still, when inspecting the signal with ursp_fft.py, the signal is not at baseband, but offset by approx. 500kHz KD7LMO's setup seems to bring L1 down to approx. -4kHz. At least the signals I acquire are centered about -4kHz. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] tuning usrp from within gr block?!
steve wrote: Hi, is it possible to change the frequency/band of the USRP from within a gr block? Is it possible to write a python-only block (without c++)? If so, your c++ block could feed an output signal what frequency to tune to the python-only block which would tune the USRP. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] [Fwd: [FFTW-announce] FFTW 3.2-alpha2 is available, Cell support, MPI]
Marcus Leech wrote: On a related subject, FFTW supports multi-threaded FFTs. Is there support for that in Gnu Radio yet, perhaps enabled automatically if it's running on a multi-CPU system? On another related note, I just found GPUFFTW (unrelated to FFTW) which runs FFTs on your GPU (graphics card) which apparently has parallel processing facilities. CHris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] DBSRX: Tune the LO from python
Is it possible to set the DBSRX's LO frequency and the FPGA DDC independently? Currently you can set the single quantity (LO - DCC) using the USRP's tune member function. When f = 1.57542GHz, I do not like GNURadio's choice of LO = 1.5755 GHz DDC = 80KHz The board seems to put out a signal at 1.5760 GHz when the LO is tuned to 1.5755 GHz which is not present when the LO is tuned to slightly higher freqs. I would like to tune the LO to the higher freq and use a larger DDC. Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] My block falling behind the USRP
What happens when a c++ block I write cannot keep up with the data the USRP is producing? In other words, my c++ block cannot keep up with real time. Is there a way to tell (in c++) that I am falling behind? Thank you! Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] OFDM
Robert McGwier wrote: In the n4hy developers branch, we spent today adding some new code and Congratulations on the cleanup! What is ofdm? What is n4hy? Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Two DBSRX boards: same clock/LO
Two DBRSX boards and one USRP: Are the two signals sampled at the exact same time? If not, how would the errors be described? I will be looking at the difference in phase between the signals received by each DBRSX. Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Two DBSRX boards: same clock/LO
Matt Ettus wrote: The signals are sampled at the same time. Thanks for the quick reply. Is this for all versions of the USRP and DBSRX? Chris PS: My USRP: Gnuradio Rev 3 1-3-2005 My DBSRX: Rev 2.0 ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GPS with DBSRX
Gregory W Heckler wrote: Has anyone successfully collected any GPS L1 data with the DBSRX Yes, I think this guy(*) used the DBSRX. He includes the collection scripts on his site as well: http://www.kd7lmo.net/ground_gnuradio_ota.html (*) I hate to call him this guy but he keeps his true identity secret! Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Trying to capture/play FM.
George Barrinuevo wrote: When I tried it, the playback sounds like the sound is playing in slow motion. This means you are playing it back with a different sample rate than the one you used to record it. The recording and playback script should have parameters for sample rate. Make sure you use the same number in each. Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Request..
1. buy a USRP 2. buy the TV tuner for the USRP 3. Install GNUradio 4. Run the example usrp_wfm_rcv.py This example uses the USRP and TV tuner as an FM radio receiver. In addition, this example produces a spectrum analyzer plot of the output of the TV tuner. Chris Alex Miua wrote: Dear Mr Blossom, How are you doing ? I came across many websites which mentioned your name and I guess that you are an expert on GNURadio. Could you please guide me in the right direction? I wish to make a software Radio Spectrum analyzer using a TV tuner card or USRP. Is it possible ? Where can I start reading about this in your opinion. I look forward to your advice. Thank you, Alex. Do you Yahoo!? Everyone is raving about the all-new Yahoo! Mail beta. http://new.mail.yahoo.com ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] KD7LMO GPS sample and sample rate nomenclature
[EMAIL PROTECTED] wrote: Either I recorded them as 64-bit floats (double) or I did the conversion from time in seconds to samples incorrectly. The capture script I wrote is located at: mgray, Thanks for the response. Your script looks fine to me, but I'll try running it. Perhaps you typed one second at the command prompt. I tried to read the data as 64 bit floats, but it looked strange (typical values 1e13) and I quickly gave up on that. It appears that the first 7000 samples are bad. I attached a plot of the mag of the first 1. The remainder look like the last chunk on the plot. I still cannot acquire a signal, but I'm working on that (could be my fault). BTW, I am working with gps_4m_complex.21Apr2005.dat Thanks, Chris PS: attachment rejected by gnu.org ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] KD7LMO GPS sample and sample rate nomenclature
Chris Stankevitz wrote: PS: attachment rejected by gnu.org I put it here: http://www.stankevitz.com/temp/samples.gif ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] ImportError: No module named wx
Larry wrote: I got an ImportError: No module named wx error Is wx in your pythonpath? Try this: [EMAIL PROTECTED] ~ $ python Python 2.4.3 (#1, Oct 13 2006, 16:57:39) [GCC 4.1.1 (Gentoo 4.1.1)] on linux2 Type help, copyright, credits or license for more information. import sys print sys.path ['', '/usr/lib/portage/pym', '/usr/lib/python24.zip', '/usr/lib/python2.4', '/usr/lib/python2.4/plat-linux2', '/usr/lib/python2.4/lib-tk', '/usr/lib/python2.4/lib-dynload', '/usr/lib/python2.4/site-packages', '/usr/lib/python2.4/site-packages/Numeric', '/usr/lib/python2.4/site-packages/dbus', '/usr/local/lib/python2.4/site-packages', '/usr/lib/python2.4/site-packages/gtk-2.0', '/usr/lib/python2.4/site-packages/wx-2.6-gtk2-unicode'] Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Sample rate nomenclature
Hi guys, Q1: When using USRP source_c (complex) with decimation == 8, am I getting 4 million complex samples per second? 64Mhz / 8 = 8MHz floats = 4MHz complex Q2: If I saved that data to a file and shared it with people, would I advertise it as Complex data, 4 million samples per second? Q3: If someone read that in using file_source(gr.sizeof_gr_complex, file.in) and wanted to perform an FFT, what would he specify as the sample rate to the fft_sink_c(sample_rate=x)? My guess is sample_rate=4e6. Thank you! Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Sample rate nomenclature
Matt Ettus wrote: Q1: When using USRP source_c (complex) with decimation == 8, am I 64 MS/s complex samples / 8 = 8 MS/s complex Okay. That's certainly easy to remember. Does float act the same way? I was under the impression you sacrifice something (samples per second) when you move from float to complex sampling. source_c, decim == 8: 8 MS/s source_f, decim == 8: ? MS/s Thanks, Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] SWIG compilation speedup!
Berndt Josef Wulf wrote: I can't see the point for doing so. I don't care if its takes me 15 minutes or 30 minutes to compile all GNU Radio. Maybe we can add a special option to slow down compiling for you! :) ./configure --enable-slow-compiling Chris ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Using RFX2400 from C++
Dan, Eric, all: I am interested in the same and am willing to help out. For now I'd be happy with just getting the bits from the USRP (i.e. no graph theory). Chris Dan Halperin wrote: Hi, I'm trying to get the code together to enable the RFX2400 board from a C++ program. I'm mostly looking in usrp.py, usrp1.py, db_base.py, and db_flexrf.py and copying commands like write_io and write_oe into their C++ versions. Is there good documentation on all of these various commands, and/or is there an easier way to use the Python code to instantiate the usrp data structure for me? Thanks, Dan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
